The present invention relates to a storage medium driving device which ensures the security of the program stored in the medium against unauthorized use or other illegal copying, and also to a storage medium and a method capable of ensuring the program security, wherein the storage medium is a detachable medium such as a digital video disk, CD-ROM, or magneto-optical disk.
There are various methods known in the art for ensuring the security of programs and data stored in media. One of them is to devise such a program as to guard against unauthorized use, and another is to devise an executing program of a processor like a personal computer so as to be safe from illegal access.
However, if the personal computer is unconditionally allowed to fetch the program stored in the medium, it is difficult to protect the program from illegal copying, and therefore, it is preferable to limit the ability to fetch the program to the medium driving device.
The level of security differs program by program, which means that each storage medium must be provided with its own level of security. To achieve this result, firmware is required for controlling a storage medium driving device. However, the firmware must have a sufficient capacity for accommodating a built-in memory, thereby increasing the production costs of the storage medium driving devices.